Plug for rubber treads.



' G, E, ROLLINS,

PLUG FOR RUBBER TBEADS- mucmon maxim/W1 Isis Patented Feb- 27,1917.

WITNESS A INVENTOH,

' [UIFGf [fill/4Q I '9 my 577 ATTOH/VEKi GEORGE E. ROLLINS, F BEGGKTON, MASEAGHUSE'ETS.

YL'D'G FOR RUBBER TBEADS.

Specification of Letters Patent. Patgmlggfl F aky, 2'? 191?,

Application filed May 1, 1918. Serial 1i 0. 94:,542',

To all whom it may concern: Be it known that l, Gnoncn E. Romans,

acitizen of the United States, residing at Brockton, in the county oillymouth, in the 5 State of Massachusetts, have invented a certain new and useful Improvement in Plugs for Rubber Treads, of which the following,

isa specification, reference being had to the accompanying drawings.

This invention relates to treads, and 1s moreespecially concerned with that class of treads such as soles and heels of footwear, in'which plugs are inserted or Otherwise built into the treads, in order to increase the tractive and wearing qualities, and the general eiii'ciency of such treads. -My present invention relates more particularly to means taken in. connection with the accompanying drawings showing two specific embodiments thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings: 7 Figure l is a bottom plan of a tread memberYin the form of a shoe sole and heel having plugs embodying my invention secured in the heel.

Fig. 2' is a Vertical sectional view on an enlarged scale on line 2-2 of Fig. 1; and v Fig. 8 is a' relatively enlarged central vertical sectional view of an improved form of plug embodying my invention.

Referring to the drawings, and to both embodiments of my invention which I have selected for illustration, I have there shown a tread member a in the form of a shoe heel,- the same beiu made preferablyvof vulcan 45 ized. rubber. In this tread member is em bedded e wear-resisting member 2'), which may be of-solid rubber, as illustrated in Fig. 8, or of rubberized fabric coiled upon itself, us in Figs. 1 and 2. This wear-resisting 50 member has aportion presented at the tread surface to receive the wear and to increase the tractive qualities of the tread. The

wear-resisting member has another contiguchance become loosened one portion, herein a lateral surface, contacting with the tread. member a, as clearly shown in Fig. 2, thus providing a direct union between these two parts.

As a means for anchoring the wear-resisting member in the tread member, I have herein provided suitable means, including a metallic anchor member 0, preferably of cupped disk form, as best seen in Fig. 3.

In both forms, the cup is of such size that the plug proper, or wear-resisting member fits tightly therein. The annular rim of the cup projects laterally from the wean-resisting member, and is laterally interposed be tween the latter and the tread member, but preferably does not extend to the tread S111? face. By terminating it short of the tread surface, the cup is prevented from striking floors and pavements. If the cup'were to strike, it would produce an unpleasant noise, floors, rugs and carpets would be apt to be injured, and the cup itself would be likely to be distorted and injured Still other ad vantages will readily suggest themselves As a further means for anchoring the" plugin the tread member, it may be provided with suitable lateral pro ections, herein in the form of a dowel pin 0?, which 1s passed through the annular walls of the cup 0, as best shown in Fig. 3, this arrangement being alsoindicated in Fig. 2. The projecting ends of the dowel pin laterally intcrengag'e with the tread memberintec mediate the upper and lower surfaces" of the latter, which, by the way, it isuto'i be observed, is herein formed as one piece, and by this means, the plug is permanently united with the tread member, and is locked against movement in all directions. The intermediate portion of the dowel pin passes through the plug proper, or wear-resisting member F), and interlocks therewith, thus effectually locking the latter against inovement in all. directions. Thus, it is apparent that, even though the slug should by any in the tread member, it cannot escape because it is interlocked therewith and held against move ment in either direction As an additional means for securing the plug, I prefer to provide openings in the bottom ofthe cup, as shown in Fin 2 3, in order that the rubber. of 7 o; member may flow intoand through said openings, and become vulcanizecl to the plug,

By prefenence, 1 form the plug 3) with one or more raclial ribs 6, which are thus adapt ed to be seated in corresponding notches in the rim of the cup 0, to aid in preventing the rotation of the plug in the cup, as will he evident from an inspection of Figs. 1. and 2. It Will be evident that, in the form shown in Fiex 2, and Where the rim of the cup is notched, the ribs actually project through these notches into direct contact with the tread member in the plane of the cup rim.- This. will he clearly apparent from an inspection of Fig. 2, when it is considered that the plane of the section line 52-42 passes through the rihs. v

As a still further means for securing the plug in the tread member, by preference, I provide a hard rubber tubular core 7 in the center of the plug 7) (see Figs. 1 and 2), the central opening 01" which core is some- What smaller than the head of a milk,

driven through the core and the cup into the treaci neniher, as will be understood. by referenc o Fig. 2 of the drawings. As the nail is thus driven through the core, the nail head forcibly expands the core, ancl the latter in tending to contract after the passage of the nail head, effectually loc Is the nail against accidental misplacement or Withdrawal. This construction also conceals the nail from View, and avoiols disfiguring the more or less ornamental sun i ace of the tread member,

Any clesiretl number of plugs may be located. in the heel, and they may also he providecl in the sole of the shoe if desir cl. The plugs may be cheaply produced, and

when. anchored as 11 have clescrihed in cle tail, it IS impossible to remove them from? the tread member Without actually cutting the rnhher of the latter away from the plugs, since the latter are permanently interlocked "with the treatl member.

the operation of melting my (lee zibed member 6*, is seated. in. the cup or member 0, ancl is suitably securccl as by means of the dowel pin, turejthus proviclec in the mold in which the ii- 363C 1: h to be formecl, anti in the operation 0" canizing the tread member, the ph 11 plugs are fixedly anchorecl therein.

-While l have herein shown l ciescr'ihel two forms embodiments of chor v inven- 'tion for illustrative purposes, and have (liscloseci and CliSCUCl in detail the construe-- tion and. arrangement in idental to two I is to he on (lerstoocl that the invention amass. neither to the mere cletails or relative ar rangement of parts, nor to its specific eniboilinients herein sl'iown, that extensive her having two opposite surfaces one o in saicl member, said plug comprising; plugs, the plug proper, or Wear-i*es1s'1'ng' deviations from the illustratecl forms or embodiments of the invention may he made Without departing fromthe principles thereof.

Having thus described two specific embodiments of my inventioi'i,- What I claim and desire by Letters Patent to secure is 1. A, heel comprising a rubber body member having seated and vulcanized. therein, a plug comprising cup, a ivear resisting member, a dowel-pin locking said. member in said. cup, and means for anchoring thereceive said Wear-resisting member, anti a dowel pin extending through the lateral portions of the cup and Wear-resisting member; the encl portions of the clowel. pin be ing extended beyond the cup, and terminat ing at each entl Within the heel.

4t. in combination, a one piece resilient tread member having two opposite surfaces one or" which is a tread. surface, a plug ernheclclecl in said member, saiol plug compris ing a weariesistin "niem'her having a per tion presented; at the treacl surface, and look-- ing means extending into said treacl their.

his and into said Wear-resisting member in the same general direction as saici surfaces and laterally interlocking with said trcael member and with saici Wear-resisting mEIi1- hen intermediate said opposite surfaces.

5. in. combination, a resilient tread meinwhich a tread surface, a plug enilaeclc Wear-res'sting member having portion feel the tread surface, and; anchor consistingoi a iueniher havn inerposo between anrl directly e:

saicl tree-cl member and saicl 'Wea" and. having a part pro rem saitl Wall from op respectively, thereof into gcoking engagement with hoth oi sairi --moers thereby to lock saici wean 16SlStll'l 231811161 to sail anchoring mean to loci; said anchoring means to memh I v n combination, a resilient treacl her having a tread surface, a plug; en's heckled in said member, said. alng comprisng a Weanresisting member having pen presentecl at the surface, entitling hit-o, ant

F i2 sam locking with, said wear-resisting member and laterally into and interlocking with. said tread member to secure said plug in said tread-member.

7. In combination, a resilient tread mem her having a tread surface, a plug embedded in said member, said plug comprising a wear-resisting member having a.

portion presentedat the tread-surface, and

fastening means extending transversely of 10' the sides of said Wear-resisting member entirely through the latter and laterally into 

